Department of Atmospheric and Oceanic Sciences, UCLA 405 Hilgard Ave., Los Angeles, CA 90095-1565, USA
Department of Astronomy and Space Science, College of Natural Sciences and Institute for Basic Science Research, Chungbuk National University, 48 Gaeshin-dong, Heungduk-gu, Cheongju, Chungbuk, 361-763 Korea, Republic of
Department of Atmospheric and Oceanic Sciences, UCLA 405 Hilgard Ave., Los Angeles, CA 90095-1565, USA
Space Sciences Laboratory, University of California 7 Gauss Way, Berkeley, CA 94720-7450, USA